Ok, some progress: I have found that I can export all my online Yahoo Contacts to a single VCF file (Yahoo is also good at importing contacts from other sources, so it's a good Contacts exchange mechanism).

I can then (in theory) import multiple contacts in one VCF file to gpe Contacts on the N800. I don't really care about sync, since this can be done occasionally as a one-shot update.

Unfortunately I have to say that vCard importer in gpe Contacts is one of the least robust pieces of software I have ever encountered (I have a more colorful description, but I don't think you need to hear it ). It's incredibly picky about what it will accept, and it if there's a single error anywhere in the entire import file, it aborts without importing anything, and displays only "Import failed" with no indication of what or where the error was.

So far in about 100 tests I have gotten about 1/2 of my contacts imported, stumbling over one error after another by process of elimination. I obviously haven't found them all yet. Here's some of the ones I know about:
- While gpe Contacts will accept the qualification "CHARSET=UTF-8" (used by Yahoo), it apparently doesn't know what that is, so special characters in the forms =hh or &#hhh; or &code; will not be translated.
- Any appearance of any of these codes in the N or FN (name) fields will cause import of the VCF file to fail
- Since the "=" character has special meaning in VCF files (line continuation), any other appearance of this character in the file at all causes import to fail
- gpe Contacts also doesn't like single or double quote characters to appear anywhere, or it will cause import of the file to fail
- Yahoo uses a 2-digit number in the Rev field, while gpe Contacts apparently expects a date+time value in the format used by Outlook. Instead of being ignored, the Yahoo 2-digit value causes import of the file to fail.

And BTW, editing a VCF file with Windows Notepad corrupts it invisibly for Linux purposes by adding a 3 character UTF-8 marker header to the file (EF BB BF - I have to remember to remove it with Hexedit after every edit).

Thank goodness for Wizard Mounter allowing direct access between systems, or these tests would take forever. I'm still hopeful that I'll be able to develop a simple set of automated edits to apply that will let me transfer the entire Yahoo file in one shot.